Vehicular camera

This application is based on and claims priority under 35 USC 119 from Japanese Patent Application No. 2023-121955 filed on Jul. 26, 2023, the entire content of which is incorporated herein by reference.

The present disclosure relates to a vehicular camera.

With demands for improvements in vehicle safety, introduction of autonomous driving functions and the like in recent years, development of vehicular cameras that are mounted on vehicles and capture the inside and outside of the vehicles have become active as disclosed in, for example, JP2014-075825A and JP2019-067740A.

Required levels relating to safety, automatic driving functions, and the like, which are required for vehicles, are improved, and further improvement in performance and the like are also required for vehicular cameras.

The present disclosure relates to a technique for providing a new vehicular camera capable of ensuring conduction between two shields while achieving ease of assembly.

A vehicular camera includes a lens unit including at least one lens, a first tubular portion configured to accommodate the at least one lens, and a flange portion formed around the first tubular portion with an optical axis of the lens as a center and having a first flange surface, a second flange surface opposite to the first flange surface, and a flange end surface connecting the first flange surface and the second flange surface, a circuit board having a first surface, a second surface opposite to the first surface, and an end surface connecting the first surface and the second surface, an imaging element mounted on the first surface of the circuit board and disposed on the optical axis of the at least one lens, a housing to which the flange portion of the lens unit is fixed, the housing having a second tubular portion configured to accommodate at least the circuit board and the imaging element, a first shield made of metal and disposed in an internal space formed by the second tubular portion of the housing and the second flange surface of the flange portion of the lens unit so as to surround the circuit board, and a second shield made of metal and disposed along the second flange surface of the flange portion of the lens unit so as to face the first surface of the circuit board, the second shield having a first hole corresponding to the imaging element. At least a part of the flange end surface of the flange portion of the lens unit faces an inner surface of the first shield. The second shield includes at least one contact portion disposed along the flange end surface of the flange portion from the second flange surface of the flange portion on at least one side in a plan view of the flange portion. At least a part of the contact portion of the second shield is in contact with the first shield. A shield end of the first shield is disposed at a position closer to the first flange surface of the flange portion than the at least a part of the contact portion of the second shield in a direction along the optical axis.

According to the present disclosure, at least one contact portion of the second shield is disposed along the flange end surface from the second flange surface of the flange portion. Thus, when the lens unit and the second shield are inserted into the housing in a state in which the second shield is disposed on the second flange surface of the flange portion of the lens unit, the contact portion does not become an obstacle to insertion, and thus the ease of assembly of the vehicular camera can be achieved.

Further, the shield end of the first shield is disposed at a position closer to the first flange surface of the flange portion than at least a part of the contact portion of the second shield that is in contact with the first shield. Thus, at least a part of the contact portion of the second shield is reliably in contact with the first shield, and thus conduction between the first shield and the second shield can be ensured, and the first shield and the second shield can be maintained at the same potential.

Hereinafter, an embodiment that specifically discloses a vehicular camera according to the present disclosure will be described in detail with reference to the drawings as appropriate. However, unnecessarily detailed descriptions may be omitted. For example, detailed descriptions of already well-known matters and redundant descriptions of substantially the same configuration may be omitted. This is to avoid unnecessary redundancy of the following description and facilitate understanding of those skilled in the art. It should be noted that the accompanying drawings and the following description are provided for those skilled in the art to sufficiently understand the present disclosure, and are not intended to limit the subject matter described in the claims.

is an example of a vehicle, and is a top view of the vehicle on which vehicular cameras are mounted. As a vehicular camera, a vehicular cameraA, a vehicular cameraB, a vehicular cameraC, and a vehicular cameraD are mounted on a vehicle V. The vehicular cameraA is a front camera, the vehicular cameraB is a rear camera, the vehicular cameraC is a right side camera, and the vehicular cameraD is a left side camera. The vehicular camerasA toD are, for example, wide-angle cameras having an angle of view of about 180°, and are disposed to capture images showing the entire periphery of the vehicle V.

For example, the vehicular cameraA is provided in a front grille of the vehicle V, and captures an image of a front region in a direction of looking down obliquely with respect to the ground. The vehicular cameraB is provided in a roof spoiler of the vehicle V, and captures an image of a rear region in a direction of looking down obliquely with respect to the ground. The vehicular cameraC and the vehicular cameraD are provided in side mirrors of the vehicle V, and capture images of lateral regions in directions of looking down obliquely with respect to the ground, respectively.

is a block diagram illustrating a connection example of the vehicular camerasA toD provided in the vehicle V shown in, a camera ECU, and a display. The camera electronic control unit (ECU)insynthesizes the images captured by the vehicular camerasA toD, and displays a synthesized image on the displayof a navigation system disposed on an instrument panel, for example. An occupant can visually recognize the displayand check a situation around the vehicle V.

is another example of the vehicle, and is a schematic diagram of a cabin of the vehicle on which the vehicular camera is mounted, andis a top view of the vehicle in. The vehicle V includes a display device(for example, an electronic rearview mirror) at an attachment position of a rearview mirror which is a front portion between a driver's seatand a passenger seatin a cabin. Further, the vehicle V is provided with the vehicular cameraat a rear side of a vehicle body.is a block diagram illustrating a connection example of the vehicular cameraprovided in the vehicle V shown in, a camera ECU, and the display device. The camera electronic control unit (ECU)inprocesses an image captured by the vehicular camera, and the display devicedisplays the image. The occupant can visually recognize the display deviceand check a rear situation of the vehicle V.

is a top perspective view of the vehicular cameraaccording to the embodiment.is a bottom perspective view of the vehicular cameraaccording to the embodiment.is a top view of the vehicular cameraaccording to the embodiment.is a view taken along a line III-III in, andis an enlarged view of a region A in. A Z axis along an optical axis of a lens of a lens unitin the vehicular camera(in other words, an axis along a height direction of the vehicular camera), an X axis that is a first axis of two axes orthogonal to the Z axis, and a Y axis that is a second axis of the two axes orthogonal to the Z axis and is also orthogonal to the X axis are defined and used in the following description.

The vehicular cameraaccording to the present embodiment includes a cap, a ring member, a lens unit, a circuit board, an imaging element, a housing, a first shield, and a second shield. The capis a member that is attached to the ring memberand protects the lens unit.

The ring memberis implemented by a rectangular annular member having a flat plate shape in a plan view (a line of sight when the vehicular camerais viewed along a cross section orthogonal to the Z axis, the same applies hereinafter), and is welded to the lens unitand the housingby laser welding. An inner peripheral surface of the ring memberfaces, in an XY plane direction, an outer peripheral surface of a first tubular portionthat constitutes a lens barrelof the lens unit. An inner diameter of the ring memberhas a length that allows the first tubular portion(the lens barrel) of the lens unitto be inserted.

The ring memberis formed of a first resin having predetermined light transmittance. The first resin is made of a material containing a light-transmitting resin. For example, the light-transmitting resin is formed of a polyester resin, a polyolefin resin, a polyamide resin, a vinyl chloride resin, a fluorine resin, or the like. As the polyester resin, polybutylene terephthalate (PBT), polyethylene terephthalate (PET), or the like can be used. As the polyolefin resin, polyethylene, polypropylene, or the like can be used. One type of light-transmitting resin or a plurality of types of light-transmitting resins may be used. In addition, a coloring material, a filler, or both may be contained in a main light-transmitting resin as long as a transmission performance of a certain level or more can be achieved.

Although the ring memberhas a flat rectangular annular shape in the present embodiment, the shape is not limited thereto, and a welded portion may have a flat plate shape. Therefore, the shape is not limited to a polygonal shape such as a rectangular annular shape, and may be a circular annular shape or an annular shape other than the circular annular shape such as an elliptical annular shape. In addition, steps, thicknesses, and the like may not be uniform in portions other than the welded portion.

The lens unitincludes the first tubular portionthat constitutes the lens barrelhaving a tubular shape and has a first tubular shape, and at least one lens (not shown) disposed inside the first tubular portion. The first tubular portionhas a tubular shape, and holds a lens group including, for example, a plurality of lenses inside the first tubular portion. The respective lenses in the lens group are arranged in a state in which respective optical axes (axes extending in an up-down direction of the paper inand along the Z axis) are aligned with each other, and constitute the lens group used for capturing images of the inside and outside of a vehicle body of a vehicle.

The lens unithas a flange-shaped flange portionprotruding from the outer peripheral surface toward the outside of the first tubular portion. The flange portionis disposed outside the first tubular portionto extend outward with respect to the optical axis of at least one lens over an entire periphery around the optical axis. A cross section of the flange portionalong a radial direction has a quadrilateral shape. The flange portionis located in the vicinity of an opening of an internal space of the housingto be described later, and protrudes toward an inner peripheral surface of the housing. At least a part of the flange portionis joined to the housingvia the ring member.

The flange portionis disposed inside a large-diameter tubular portionto be described later of the housingin the radial direction perpendicular to the optical axis, and includes a ring-shaped first flange surfacefacing the ring member, a ring-shaped second flange surfaceopposite to the first flange surface, and a flange end surfaceconnecting the first flange surfaceand the second flange surface

At least the second flange surfaceof the flange portionin the lens unitis formed of a second resin having a first light absorptivity. The second resin is made of a material containing a light-absorbing resin. As the light-absorbing resin, for example, a polyamide-based resin, an olefin-based resin, a vinyl-based resin, a styrene-based resin, an acrylic-based resin, a polyester-based resin, a polycarbonate-based resin, a polyarylate-based resin, a polysulfone-based resin, a polyphenylene oxide-based resin, a polyether sulfone-based resin, or a polyetherimide-based resin can be used. One type of light-absorbing resin or a plurality of types of light-absorbing resins may be used. A main light-absorbing resin may contain an absorbent that absorbs laser light, a coloring material, or both.

Since the second flange surfaceof the flange portionis made of the second resin, transmission of light into the internal space can be reduced. That is, the transmission of light from the outside of the vehicular camerato the inside of the vehicular cameracan be reduced. Therefore, image quality deterioration of a captured image due to halation or the like of the imaging elementcaused by transmitted light can be prevented. The entire flange portionor the entire lens unitmay be formed of the second resin.

The circuit boardis disposed in the internal space of the housing, and includes a first surface, a second surfaceopposite to the first surface, and an end surfaceconnecting the first surfaceand the second surface. However, two or more circuit boards may be provided.

The imaging elementis disposed in the internal space of the housingtogether with the circuit board, receives light transmitted through the lens unit, and captures an optical image of a subject by photoelectric conversion based on the received light to generate a captured image of the subject. The imaging elementis disposed on the optical axis of at least one lens of the lens unit. The imaging elementis mounted on the first surfaceof the circuit board, and light from the outside of the subject and the like can be easily guided to the imaging element.

The housingis a tubular member having the internal space, supports the lens unitdirectly or indirectly in some cases, and accommodates at least the circuit boardand the imaging element. The housingincludes the large-diameter tubular portionhaving a second tubular shape along the optical axis and a small-diameter tubular portionhaving a third tubular shape along the optical axis. The large-diameter tubular portionconstituting a second tubular portion has a larger cross-sectional area than the small-diameter tubular portionconstituting a third tubular portion in the XY plane direction, and has a rectangular cross section. The large-diameter tubular portionaccommodates the circuit boardand the imaging elementtherein. The small-diameter tubular portionmainly accommodates a connectorthat secures electrical connection with the outside of the vehicular camera. The large-diameter tubular portionand the small-diameter tubular portionmay be integrally formed by using a resin to be described later, and the large-diameter tubular portionand the small-diameter tubular portionprepared individually in advance may be joined by a method such as welding or screwing. Although the housinghas a rectangular tubular shape in the present embodiment, the shape is not limited thereto, and may be a polygonal tubular shape other than the rectangular tubular shape, a circular or elliptical tubular shape, or another tubular shape.

At least an end portionof the large-diameter tubular portionin the housingis formed of a third resin having a second light absorptivity. The third resin is made of a material containing a light-absorbing resin. As the light-absorbing resin, for example, a polyamide-based resin, an olefin-based resin, a vinyl-based resin, a styrene-based resin, an acrylic-based resin, a polyester-based resin, a polycarbonate-based resin, a polyarylate-based resin, a polysulfone-based resin, a polyphenylene oxide-based resin, a polyether sulfone-based resin, or a polyetherimide-based resin can be used. One type of light-absorbing resin or a plurality of types of light-absorbing resins may be used. A main light-absorbing resin may contain an absorbent that absorbs laser light, a coloring material, or both. The second light absorptivity may be the same as or different from the first light absorptivity.

Since at least the end portionof the housingis made of the third resin (that is, the material including the light-absorbing resin), the transmission of light into the internal space of the housingcan be reduced. That is, the transmission of light from the outside of the vehicular camerato the inside of the vehicular cameracan be reduced. Therefore, image quality deterioration of a captured image due to halation or the like of the imaging elementcaused by transmitted light can be prevented. The entire large-diameter tubular portionor the entire housingmay be formed of the third resin.

The ring memberis welded to the first flange surfaceof the flange portionof the lens unitand the end portionof the housingby the laser welding. That is, the flange portionof the lens unitis fixed to the end portionof the housingvia the ring member.

The first shieldis disposed so as to surround the circuit boardin an internal space formed by the large-diameter tubular portionof the housingand the second flange surfaceof the flange portionof the lens unit. The first shieldis made of metal, and is a tubular member formed by a method such as bending a metal plate or drawing a metal material. At least a part of the flange end surfaceof the flange portionof the lens unitfaces an inner surface of the first shield.

is a perspective view of a second shield. The second shieldis disposed along the second flange surfaceof the flange portionof the lens unitso as to face the first surfaceof the circuit board, and has a first holecorresponding to the imaging element. The second shieldis made of metal, and is a plate-shaped member formed by a method such as bending a metal plate.

The first shieldand the second shieldare metal members for shielding components such as the circuit boardand the imaging elementfrom external noise, and an imaging function of the vehicular camerais exhibited by a noise shielding function of the first shieldand the second shield. Since the first shieldand the second shieldare preferably kept at the same potential (a ground potential), the first shieldand the second shieldare required to be in contact with each other.

For the above contact, the second shieldincludes at least one contact portiondisposed along the flange end surfaceof the flange portionfrom the second flange surfaceof the flange portionon at least one side in a plan view of the flange portion. As shown in, at least a part of the contact portionis in contact with the first shield. A shield endon the lens unitside of the first shieldis disposed at a position closer to the first flange surfaceof the flange portionthan at least a part of the contact portionof the second shieldin a direction along the optical axis.

is a perspective view of an assembly of the lens unitand the second shield, andis a bottom view of the assembly of. In assembling the vehicular camera, the components such as the circuit boardand the imaging elementare disposed in the internal space of the housing, and then the assembly shown in FIGS.A andB is inserted into the housing. That is, before the assembly is inserted into the housing, the lens unitand the second shieldare assembled as shown in.

When the assembly is inserted into the housing, the contact portionis elastically bent inward (toward the optical axis) by the contact with the inner surface of the first shielddisposed in the housing. When the assembly is accommodated in the housing, an elastic force that tends to expand outward is generated in the contact portion, and the contact between the first shieldand the second shieldis maintained by the elastic force.

In the vehicular cameraaccording to the embodiment, at least one contact portionof the second shieldis disposed along the flange end surfaceof the flange portionfrom the second flange surfaceof the flange portion. That is, the contact portionextends in a direction opposite to an insertion direction when the assembly is inserted. Thus, when the lens unitand the second shieldare inserted into the housingin a state in which the second shieldis disposed on the second flange surfaceof the flange portionof the lens unitas shown in, the contact portionis unlikely to be an obstacle to the insertion, and the vehicular cameracan be easily assembled.

is a perspective view of a usual second shield. Unlike the embodiment of, in the usual second shield, the contact portionextends in the insertion direction of the assembly. Thus, when the lens unitand the second shieldare inserted into the housingin a state in which the usual second shieldis disposed on the second flange surfaceof the flange portionof the lens unitas shown in, the contact portionis likely to be an obstacle to the insertion (for example, caught on the end portionof the housing), and the assembly of the vehicular cameramay be complicated.

As shown in, the shield endof the first shieldis disposed at a position closer to the first flange surfaceof the flange portionthan at least a part of the contact portionof the second shieldthat is in contact with the first shield. Thus, at least a part of the contact portionof the second shieldis reliably in contact with the first shield, and thus the conduction between the first shieldand the second shieldcan be ensured, and the first shieldand the second shieldcan be maintained at the same potential.

The contact portionof the second shieldis formed by bending a metal. Accordingly, the contact portioncan be easily formed. Further, at least a part of the contact portionis a tip portion (for example, a first contact portion) of the contact portion. The tip portion (for example, the first contact portion) is a location where the elastic force that allows the contact portionto expand is largest, and thus it is possible to ensure strong contact between the first shieldand the contact portion.

Hereinafter, details of the configuration will be further described. The second shieldhas a first shape having at least a first side, a second side, a third side, and a fourth sidein a plan view of the second shield. At least one contact portionof the second shieldincludes the first contact portion, a second contact portion, a third contact portion, and a fourth contact portion. The first contact portionis disposed on the first side, the second contact portionis disposed on the second side, the third contact portionis disposed on the third side, and the fourth contact portionis disposed on the fourth side

That is, the second shieldhas at least four contact portions, and thus it is possible to ensure conduction between the first shieldand the second shieldmore reliably.

The flange portionof the lens unithas a second shape in the plan view of the flange portion. The flange end surfaceof the flange portionincludes at least a first flange end surface, a second flange end surface, a third flange end surface, and a fourth flange end surface.

Here, the first flange end surfaceof the flange portionconnects the first flange surfaceand the second flange surface, and corresponds to the first sideand the first contact portionof the second shield. The second flange end surfaceconnects the first flange surfaceand the second flange surface, and corresponds to the second sideand the second contact portionof the second shield. The third flange end surfaceconnects the first flange surfaceand the second flange surface, and corresponds to the third sideand the third contact portionof the second shield. The fourth flange end surface connects the first flange surfaceand the second flange surface, and corresponds to the fourth sideand the fourth contact portionof the second shield.

Accordingly, the flange portionof the lens unithas at least four flange end surfaces, and at least four contact portionsof the second shieldcan be disposed along the four flange end surfaces

Furthermore, the first flange end surfaceof the flange portionhas a first concave portionthat accommodates the first contact portionof the second shield. The second flange end surfacehas a second concave portionthat accommodates the second contact portionof the second shield. The third flange end surfacehas a third concave portionthat accommodates the third contact portionof the second shield. The fourth flange end surfacehas a fourth concave portionthat accommodates the fourth contact portionof the second shield.

Each of the first concave portionto the fourth concave portionis formed by recessing each corresponding flange end surfaceinward (toward the optical axis). Such a concave portion can be formed by, for example, a metal mold for resin injection or cutting the flange end surfacewhen the lens unitincluding the flange portionis formed.

Accordingly, since the concave portion formed in the flange end surfaceaccommodates the contact portionof the second shield, it is possible to prevent the contact portionfrom excessively protruding to the housingside beyond the flange end surface, and to prevent a gap from being generated between the flange end surfaceand the housing.

Furthermore, the second shieldincludes a first engaging portionextending from the second flange surfaceof the flange portionalong the first flange end surfaceon the first side, a second engaging portionextending from the second flange surfaceof the flange portionalong the second flange end surfaceon the second side, a third engaging portionextending from the second flange surfaceof the flange portionalong the third flange end surfaceon the third sideof the second shield, and a fourth engaging portionextending from the second flange surfaceof the flange portionalong the fourth flange end surfaceon the fourth sideof the second shield.

The first engaging portionengages with a first engaged portionformed on the first flange end surfaceof the flange portionof the lens unit. The second engaging portionengages with a second engaged portionformed on the second flange end surfaceof the flange portion. The third engaging portionengages with a third engaged portionformed on the third flange end surfaceof the flange portion. The fourth engaging portionengages with a fourth engaged portionformed on the fourth flange end surfaceof the flange portion.

The second shieldcan be fixed to the flange portionof the lens unitby engaging the first engaging portionto the fourth engaging portionof the second shieldwith the first engaged portionto the fourth engaged portionof the flange portion, respectively.